Dataset Information

Deficiency of histone lysine methyltransferase SETDB2 in hematopoietic cells promotes vascular inflammation and accelerates atherosclerosis

ABSTRACT: Epigenetic modifications of the genome, including DNA methylation, histone methylation/acetylation and noncoding RNAs, have been reported to play a fundamental role in regulating immune response during the progression of atherosclerosis. SETDB2 is a member of the KMT1 family of lysine methyltransferases and members of this family typically methylate histone H3 Lys9 (H3K9), an epigenetic mark associated with gene silencing and previous studies have shown SETDB2 is involved in innate and adaptive immunity, the pro-inflammatory response and hepatic lipid metabolism. Here we report that the expression of SETDB2 is markedly upregulated in human and murine atherosclerotic lesions. The upregulation of SETDB2 is observed in pro-inflammatory M1, but not anti-inflammatory M2 macrophages (MΦ). Notably, we found that genetic deletion of SETDB2 in hematopoietic cells promotes vascular inflammation and enhances the progression of atherosclerosis in bone marrow transfer studies in LDLR knockout mice. Single cell RNA-Seq analysis in isolated CD45+ cells from atherosclerotic plaques from mice with SETDB2 deficient bone marrow revealed a significant increase in inflammatory macrophage population and enhanced expression of genes involved in inflammation, myeloid cell recruitment and lipid metabolism. Additionally, we found that loss of SETDB2 in hematopoietic cells is associated with macrophage accumulation in atherosclerotic lesions, macrophage proliferation and attenuated efferocytosis. Overall, these studies identify SETDB2 as an important inflammatory cell regulator that controls macrophage activation in atherosclerotic plaques.

ORGANISM(S): Mus musculus

PROVIDER: GSE169112 | GEO | 2021/03/18

REPOSITORIES: GEO

ACCESS DATA

Similar Datasets

Project description:Cardiovascular disease is the leading cause of death in developed countries and there is compelling evidence that the majority of these fatalities are secondary to rupture of unstable atherosclerotic plaques. However, the mechanisms that control plaque stability are poorly understood, although it is widely believed that plaques having a decreased ratio of cells positive for smooth muscle cell (SMC) markers such as ACTA2 relative to macrophage markers are more likely to rupture. Herein we employMyh11-CreERT2 ROSA floxed STOP eYFP Apoe-/- mice to trace SMC lineage and show that traditional methods for detecting SMCs based on immunostaining for SMC markers like ACTA2 are unable to detect 82% of SMC-derived cells within advanced atherosclerotic lesions. Moreover, we show that these SMC-derived cells within advanced lesions exhibit multiple phenotypes including activation of multiple markers of macrophages, mesenchymal stem cells (MSC), and myofibroblasts (MF). Importantly, we show that SMC-derived macrophage like cells are phagocytic based on electron microscope YFP immunolabeling. In addition, results of single cell epigenetic assays developed in our lab shows that nearly 20% of macrophage-like cells within human lesions are of SMC not myeloid origin. These phenotypic transitions appear to be critical in lesion pathogenesis, in that we show that SMC-specific conditional knockout (KO) of the pluripotency factor, Krüppel-like factor 4 (KLF4), resulted in marked reductions in lesion size, increases in multiple indices of plaque stability, and reduced numbers of SMC-derived MSC- and macrophage-like cells. Finally, we show that cholesterol loading of cultured SMC is associated with activation of multiple markers of macrophages and MSC, secretion of pro-inflammatory cytokines, and increased phagocytosis, all of which are Klf4 dependent. Taken together, results indicate that the contribution of SMCs within atherosclerotic plaques has been greatly underestimated, and that loss of Klf4 within SMC result in major changes in SMC phenotype and function that play a major role in lesion pathogenesis. Examination of KLF4 transcription factor in an atherosclerosis setting

Project description:Background: Atherosclerosis leads high mortality, highlighting an urgent need for new therapeutic strategies. Protein kinases orchestrate multiple cellular events in atherosclerosis and may provide new therapeutic targets for atherosclerosis. Here, we identified a protein kinase, WEE1 G2 checkpoint kinase (WEE1), promoting inflammatory response in atherosclerosis. Methods: The ApoE-/- mice without macrophage-specific WEE1 deletion (ApoE-/-WEE1f/f) and ApoE-/- mice with macrophage-specific WEE1 deletion (ApoE-/-WEE1MCKO) were generated using bone marrow transplantation. These mice and WEE1 inhibitor MK1775 were used in a high-fat diet (HFD)-induced atherosclerotic model. Human atherosclerotic tissues, mouse primary peritoneal macrophages (MPMs), 293T cells, and recombinant proteins were utilized to investigate the pathogenic role and underlying mechanisms of WEE1. Results: We identified up-regulated p-WEE1 in macrophages in atherosclerotic lesions of HFD-fed ApoE-/- mice. Transcriptome sequencing analysis indicated that WEE1 promotes oxLDL-induced inflammation in macrophages. We then demonstrated that macrophage-specific deletion or pharmacological inhibition of WEE1 attenuates atherosclerosis by reducing inflammation both in vivo and in vitro. The overexpression of wild-type WEE1 or activating-mutant WEE1, but not inactivating-mutant WEE1, exacerbates inflammation in macrophages. Mechanistically, transcriptome sequencing analysis and co-immunoprecipitation followed by quantitative proteomics analysis identified p65 as a binding protein of WEE1. We confirmed that WEE1 directly interacts with the RHD domain of p65 via kinase domain and phosphorylates p65 at S536, thereby facilitating subsequent NF-κB activation and inflammatory response in macrophages. Conclusions: Our findings demonstrated that macrophage WEE1 promotes inflammatory atherosclerosis by directly binding to p65 and phosphorylate it at S536. This study provides WEE1 as a new p65 regulator in inflammation and a potential therapeutic target for atherosclerosis.

Project description:Regression of atherosclerosis is an important clinical goal, however the pathways that mediate the resolution of atherosclerotic inflammation and reversal of plaques are poorly understood. Regulatory T cells (Tregs) have been shown to be atheroprotective, however numbers of these immunosuppressive cells decrease with disease progression. Using multiple independent mouse models of atherosclerosis regression, we demonstrate that an increase in plaque Tregs is a common signature of regressing plaques. To test if Tregs are required for the resolution of atherosclerotic inflammation and plaque regression during lipid-lowering therapy, we combined CD25 monoclonal antibody (PC61 mAb)-mediated Treg depletion with single-cell RNA-sequencing of immune cells in the plaque and conventional analyses of atherosclerosis. Single cell RNA-sequencing revealed that Tregs from aortic plaques shared some similarity with splenic Tregs, but were distinct from skin and colon Tregs supporting recent findings of tissue-dependent Treg heterogeneity. Furthermore, Tregs from progressing plaques expressed markers of natural Tregs derived from the thymus, whereas Tregs in regressing plaques lacked Nrp1 and Helios expression, suggesting that they are induced in the periphery during lipid lowering. Treatment of atherosclerotic mice with PC61 mAb effectively depleted Tregs in the blood and peripheral tissues, including plaques, and blocked the regression of atherosclerosis induced by apoB anti-sense oligonucleotides. Morphometric analyses revealed that control antibody-treated mice showed a 40% decrease in plaque burden and macrophage content under regression conditions, whereas PC61 mAb-treated mice showed no change in plaque size or inflammatory cell content compared to baseline. Moreover, Treg depletion enhanced inflammatory signaling and blocked tissue reparative functions of macrophages in the regressing plaque, including M2-polarization, efferocytosis and sensing of specialized pro-resolving lipid mediators. Together, these data establish essential roles for Tregs in the resolution of atherosclerotic inflammation and plaque remodeling during regression.

Dataset Information

Deficiency of histone lysine methyltransferase SETDB2 in hematopoietic cells promotes vascular inflammation and accelerates atherosclerosis

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure